Electric circuit means



Oct. 17, 1961 E. QSCHWEITZER, JR 3,005,134

ELECTRIC CIRCUIT MEANS Filed Jan. 10. 1958 zNvENToE United StatesPatentV 3,005,134 f ELECTRIC CIRCUIT MEANS Edmund 0. Schweitzer, Jr.,1001 Dundee Road,

t Northbrook, lll.

' Filed Ian. 10, 1958, Ser. No. '708,187 l n sy claims. (ci. sns- 23)This invention relates, generally, to alternating current circuits andit has particular relation to multifre quency circuits. It relates to mycopending 'application Serial No. 594,322, led June 27, 1956.

Among the objects of this invention are: To connect a direct currentloaddevice through a nonlinear vresistor to a, circuit energized withalternating current compris-k ing a fundamental and a second harmonic;`to shift the phase of one of the alternating currents with respect tothat of the other in order to Vary the direction and eX- tent of owofthe direct current to the load device; to

apply the alternating currents to a motor having a perma-y nent magnetrotoror equivalen-t and to position the rotor in accordance with thephase krelation between the funda-V mental andthe second'harmonic; tovary the phase relation in order to shift the rotor from one position toanother; to provide two winding circuits through vthe motor at rightangles to each other with a non-linearresistor in each circuit; to shiftthe phase angle ofione Winding circuit with respect to that of the otherwinding circuit; to effect the phase angle 'shiftby -providing inductivemeans in one winding circuit and capacitive means in the other windingcircuit; and to employ non-linear re-y sistors having oppositecharacteristics for the two wind-y ing circuits. t y "Other objects ofthis invention will, in part, be obvious, and :in part appearhereinafter.

This invention is disclosed in the embodiments thereof shown in theaccompanying drawing and it comprises the features of construction,combination of elements and arrangement of parts that will be exempliedin the constructions hereinafter set forth and the scope of the ap-yplication of whichv/ill. be` indicated in the appended claims. I

' For a more complete understanding of the nature l andscope of thisinvention reference can be had to the following detailed description,ktaken together with the accompanying drawing, in which: p

FIGURE 1 illustrates diagrammatically one embodiment of thisinventiong'and FIGURE 2 illustrates diagrammatically a more specificapplication of the `present invention employing a motor as the loaddevice. w

"Referring no-w particularly to FIGURE l of the drawing, it will beobserved that the reference characters and 11 designate conductors whichcomprise a load circuit that is arranged to be energized withalternating current whichincludes apfundamentalA anda second harmonic,rFor this purpose a source 12 of frequency f, such as-60 cyclesy persecond, is connected through a phase shifter 13, which is energized'froma source 14 having a frequency of 2f or double thatr of the source 12,across ythe load circuit comprising the conductors 10 and 1'1. It willbe understood that the frequencies referred to are for illustrativepurposes and that higher or lower frequencies can be employed, theimportant factor however isy that the frequency of one source, i.e., thesource y14, is double that ofthe other source, i.e., the source 12.While the source 12 and phase shifter 13 are illustrated as beingconnected in series circuit relation, it will'be understood that theycan be connected in parallel. Further, it willbe understood that theycan be connected inductively rather than directly to the load circuitcomprising the conductors 10 and 11. A f

` Across the load circuit comprising the conductors 10 3,005,134Patented oci. i7, 1961' ice and 11 there are connected a non-linearresistor 15 and a load device 16 in series circuit relation therewith.The non-linear resistor 15 has no rectifying characteristics and it cancomprise a space discharge type of device such as a neon tube. y Also itmay comprise a germanium diode or a tungsten filament lamp. Itv has beenfound desirable to employ for the non-linear resistor 15 a resistor ofsilicon carbider the conductivity of which increases with increase incurrent through or voltage across it. The load device 16 can'beanyrdevice whichrequires 'for its operation the flow of direct current.

With a view to demonstrating the operating characteristics of thecircuits as shown in FIGURE l arranged as described hereinbefore, a voltmeter y17 can be connected across the load device 16k. The volt meter 17has a zero center kscale 18 with respect to which -a pointer 19 ismoved. When ythe frequencies of the sources 12,y and 14vare in phasewith eachother, then the pointer 19 swings in the direction indicated bythe arrow 20 to the maximum positive position. The pointer 19 remains atthe zero position when the double frequency 2f of the sourceA 14 iseither 90 or 270 out of phase with the frequency f of the source 12.When the frequency 2f of the source 14 is 180 vout of phase ,with thefrequency of the source 12, the pointer 19 swings yin the directionindicated -by the arrow 21 to the maximum negative position. Itwill beunderstood that the various positions of the v'phase of the frequency 2ffromthe source 14 is obtained by operating the phase shifter 13 in amanner to ybe described in more detail hereinafter.

kThe foregoing operating .characteristics will be more clearlyunderstood when it is recalled that an electromotive force having aneven harmonic is unsymmetrical with respect to the zero axis. The amountof unsymmetry is proportional to the cosine of the angle between thefundamental frequency f and the even harmonic 2f. Itofollows 4that theunsymmetry is a maximum at 0 and and a minimum at 90 and 270. When suchan unsymmetrical electromotive force is applied to aconductor whoseresistanceV 'changes with applied voltage,

` iie., Vthe non-linear resistor 15, a net unidirectional liow the signofthe cosine changes from positive to negative.

'Referring nowparticularly to FIGURE 2 of the drawing, t will beobserved that the source 12 of frequency f employed together with thephase shifter 13 and the source 14 of the frequency 2f. Here the source14 is illustrated as being atthree phase source and the combinationrisarranged as illustrated in FIGURE 1 to energize thev load circuitcomprising the conductors 10 and 11 Fwithalternating current which iscomposed of a fundamental anda second harmonic. t Since itis desiredthat a certain amount of power be drawn rfromthe sources 132i` and 14,va phase shifter 13 is employed which permits this with out distortionresulting'fromr the use of power'for operating a device.

Under these' circumstances the phase shifter 13 can comprise a-f'statorcore 22 around which therev is a stator three phase :source 14, asshown. Mounted for rotation within-the stator core 22 and stator windingZ3' is a rotor 24 which is provided with ya rotor winding 25, the rotor24 being mounted for rotation on a yshaft 26 which is indicated ascarrying a pointer 27 the position of which corresponds tothe positionof the rotor 24. Slip rings 28 are provided for making connection to therotor wind- `ing ZSin conventional manner. As shown in the drawing therotor winding 25 in Whichthe frequency 2f is induced is in series withthe frequency f from the source 12. The phase relationship between thefrequency of the source 12 and the frequency from the source 14 can beadjusted by changing the position of the rotor 2.4 which is indicated bythe pointer Z7. This ycan be done manually or it can be accomplishedthrough the agency of a motor, such as a synchronous motor, which woulddrive the rotor 24 at a predetermined speed.

The output of the source 12 generating a fundamental frequency and theoutput of the source 14 generating a double frequency or second harmonicof the frequency generated by the source 12, controlled by the phaseshifter 13, can be employed for controlling the operation of a motorthat is indicated, generally, at 30.

'I'he motor 30 includes a rotor in the form of annular core 31 of ofpermanent magnet material which is magnetized, as indicated, along adiameter. It is preferable to employ the annular form for the core 3i1although it will be understood that a bar type of rotor could beemployed. Also an electro magnet rather than a permanent magnet can beemployed for the rotor of the motor 30. The annular core 31 is mountedon a circular hub 32 which in turn is mounted on a shaft 33 whichcarries a pointer 34. In accordance with this invention the pointer 34rotates synchronous-ly with the pointer 27. If the phase shifter 13 wereemployedfor shifting the phase of the frequency f with respect to thephase of the frequency 2f, the pointer 34 would rotate through 360 foreach 180 rotation of the pointer 27.

Surrounding the annular core 311 is a core 35, annular in form and madeof transformer steel. It may be made up of a single strip of transformersteel spirally wound to provide the annular core shown. Pairs ofwindings 3636 and 37-37 are provided on the core 35. For illustrativepurposes they are shown in spaced relation to the core 35. It will beunderstood that each of these windings is in the form of a coil aroundthe core 35 and they are connected, as shown, so that, on ilow of directcurrent therethrough they generate magnetic elds at right angles to thediameters through the respective pairs of windings 3\6-36 and 37-37. I fdesired, a damping ring can be provided between the annular core 31 ofthe rotor and the annular core 35 of the stator.

It is desirable that the phase angle of the two circuits including thepairs of windings 36-.-3=6 and 3'7-37 be diierent. For this purpose aninductor 38 is connected in series circuit relation with the windingcircuit comprising the windings 36-,36. Included in this circuit is anonlinear resistor 39 of the type previously described. For illustrativepurposes it is pointed out that it may be formed of silicon carbide.

The other winding circuit comprising the windings 37--37 is connectedthrough a capacitor 40, having in parallel therewith a resistor 41, andthrough a non-linear resistor 42. It will be observed that the twowindings circuits are connected in parallel relation between theconductors and 11 which comprise the load circuit.

The inductor 38 and capacitor 40 can be omitted when the non-linearresistors 39 and 4Z have opposite characteristics. For example siliconcarbide and tungsten have opposite characteristics.

When the sources 12 and 14 are operating to generate the frequencies fand 2f, respectively, the pointer 34 takes up a position correspondingto the position of the pointer 27. On rotation of the latter, the formerfollows it. For time lkeeping purposes, the shaft 26 carrying the rotor24 can be rotated at a speed of one revolution each twelve hours and acorresponding speed of rotation of the Vpointer 34 will result. vThus itcan be employed in conjunction with a clock dial to indicate the time ofday. By providing a gear ratio of the order of one to twelve a minutehand can be operated.

Any reasonable number of motors 30' can be energized from the loadcircuit comprising the conductors 10 and 4 11. For example, all of theclocks in an oice building or manufacturing plant can be energized fromthe load circuit comprising the conductors 10 and 11 when it isenergized in the manner described hereinbefore.

In FIGURE 2, if the non-linear resistors 3-9 and 42 have similarcharacteristics, the phase angle between f and 2f that produces maximumdirect current in windings 36-36 will also produce maximum directcurrent in windings 37-37. In order to have the relative angularposition of the permanent magnet rotor 3i1 the same as that of the rotor24 of the phase shifter 13, the phase splitting inductor 38 andcapacitor resistor combination 40-.41 are used. The values ofinductance, capacitance and resistance are chosen such that, when j and2f are in phase, windings 36-36 carry maximum direct current while nodirect current flows through windings 3=7.-37. Under thesecircumstances, when the rotor Z4 of the phase shifter 13 has been turnedthrough 90 and f and 2f are 90 out of phase, windings 36-36 have nodirect current flowing therethrough and windings 3x1-37 carry maximumdirect current. 'Further rotation of the rotor 24 through an additional90 causes f and 2f to be 180 out of phase and windings 36-36 again carrymaximum direct current but in the opposite direction. Then no directcurrent ilows through windings 37-3f7, when the rotor 24 is shifted anadditional 90, f and 2f are 270 out of phase and maximum direct currentows through windings 37-437 in a reverse direction. Essentially whathappens is a change of 360 in phase between f and 2f causes theresultant unidirectional magnetic iield generated by windings 36-36 and37-37 to rotate through 360.

Since certain further changes can be made in the fore.- goingconstruction and diiferent embodiments of the invention can be madewithout departing from the spirit and scope thereof, it is intended thatall matter shown in the accompanying drawing and described herenbeforeshall be interpreted as illustrative and not in a limiting sense.

What is claimed as new is:

1. 'In combination, a first source of alternating cur, rent, a secondsource of alternating current having a frequency twice that of saidfirst source, a load circuit connected for energization to said sources,and a nonlinear resistor connected in series circuit relation with aload device and across said load circuit, said non-linear resistor beingcharacterized by being capable `of conducting current in one directionor the other whereby a direct current component Hows through -said loaddevice in one direction or the other and to an extent depending upon thephase relationship between said alternating currents.

2. In combination, a first source of alternating current, a secondsource of alternating current having a frequency twice that of saidfirst source, a load circuit connected for energization to said sources,means for shifting the phase of one of said alternating currents withrespectto the phase of the other alternating current, and a nonlinearresistor connected in series circuit relation with a load device andacross said load circuit, said non-linear resistor being characterizedby being capable of conducting current in one direction or the otherwhereby a direct current component ows through said load device in onedirection or the other and to an extent depending upon the phaserelationship between said alternating currents.

3,. In combination, a first source of alternating current, a secondsource of alternating current having a frequency twice that of saidiirst source, a load circuit connected for energization to said sources,a motor including a permanent magnet rotor and a stator having twowindlng means in spaced relation around said rotor, a non-linearresistor connected in series circuit relation with each winding meansand each resistor and its winding means connected across said loadcircuit, each non-linear resistor being characterized by being capableof conducting Wllt l. 01,1@ difction or the other whereby a directcurrent component flows through each winding means in one direction orthe other and to an extent depending upon the phase relationship betweensaid alternating currents and said rotor is moved to a positioncorresponding thereto.

4. In combination, `a first source of alternating current, a secondsource of alternating current having a frequency twice that of said rstsource, a load circuit connected for energization tosaid sources, meansfor shifting the phase of one of said alternating currents with respectto the phase of the other alternatingy current, a motor including apermanent magnet rotor and a stator having two winding means in spacedrelation around said rotor, a non-linear resistor connected in seriescircuit relation with each winding means and each resistor and itswinding means connected across said load circuit, each nonlinearresistor being characterized by being capable of conducting current inone direction or the other whereby a direct current component owsthrough each winding means in one direction or the other and to anextent depending upon the phase relationship between said 6 alternatingcurrents and said rotor is moved to tion corresponding thereto.

5. The invention as set forth in claim 4 wherein each winding meanscomprises two series connected windings on diametricallyk opposite sidesof said stator and on energization with direct current generating aunidirectional magnetic eld in a direction at right angles to therespective diameter.

6. The invention as set forth in claim 4 wherein means are provided forshifting the phase angle of the circuit including one winding means withrespect to the phase angle of the circuit including the other windingmeans.

7. The invention as set forth in claim 4 wherein means are provided inthe circuit through each winding means for shifting the phase of angleof its circuit with respect to the phase angle of the circuit of theother winding means.

8. The invention `as set forth in claim 4 wherein the non-linearresistors have opposite conducting characteristics.

a posi- No references cited.

